The inventive concept relates to memory systems, semiconductor memory devices, and programming methods for semiconductor memory devices. More particularly, the inventive concept relates to memory systems including a three-dimensional, nonvolatile memory device and methods of programming same.
Semiconductor memory devices may be classified as volatile and nonvolatile according to their operating characteristics. Volatile memory devices lose stored data in the absence of applied power, and include the static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), and the like. Nonvolatile memory devices are able to retain stored data in the absence of applied power, and include the read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable and programmable ROM (EEPROM) such as flash memory, phase-change RAM (PRAM), magnetic RAM (MRAM), resistive RAM (RRAM), ferroelectric RAM (FRAM), and the like.
Flash memory has become and particularly significant type of nonvolatile memory and includes NOR type and NAND type.
In recent years, so-called three-dimensional memory architectures and structures have been proposed to further increase the integration density of flash memory. Generally speaking, three-dimensional flash memory includes one or more semiconductor structure(s) in which memory cells are stacked on a principle substrate. Compared with a conventional two-dimensional (or planar) memory, three-dimensional memory offers advantages in integration and cost. However, the reliability of the three-dimensional memory must be improved.